/*
 *  Copyright 2020 Xiaomi
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package com.xiaomi.youpin.gwdash.common;

import java.util.concurrent.locks.ReentrantReadWriteLock;

public class LogFile {
    private final ReentrantReadWriteLock readWriteLock = new ReentrantReadWriteLock(true);
    private final StringBuilder content = new StringBuilder();
    private long lastTime;

    public String read () {
        readWriteLock.readLock().lock();
        try {
            return content.toString();
        } finally {
            readWriteLock.readLock().unlock();
        }
    }

    public void write (final String msg) {
        readWriteLock.writeLock().lock();
        try {
            content.append(msg.endsWith(System.lineSeparator()) ?
                    msg : (msg + System.lineSeparator()));
            lastTime = System.currentTimeMillis();
        } finally {
            readWriteLock.writeLock().unlock();
        }
    }

    public long getTime () {
        readWriteLock.readLock().lock();
        try {
            return lastTime;
        } finally {
            readWriteLock.readLock().unlock();
        }
    }

}
